Condition-controlling device.



J. I. AYER.

CONDITION CONTROLLING DEVICE. rum/amen FILED 001*. 29, 1906,

Patented Nov. 24, 1903.

J. I. AYER.

CONDITION CONTROLLING DEVICE.

AYPLIOATION FILED 001 29, 1906.

Patented NOV. 24, 1908.

2 SHEETS-SHEET 2.

UNITED STATES PATENT OFFICE.

JAMES I. AYER, OF CAMBRIDGE, MASSACHUSETTS, ASSIGNOR TO SIMPLEX ELECTRIC HEATING COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

CONDITION-CONTROLLING DEVICE Specification of Letters Patent.

Patented Nov. 24, 1908'.

Application filed October 29, 1906. Serial No. 340,948.

To all whom it may concern:

Be it known that I, JAMES I. AYEn, a citizen of the United States, residing at Cambridge, in the county of Middlesex and State of Massachusetts,have invented an Improvement in Condition-Controlling Devices, of which the followingdescription, in connection with the accompanying drawing, is a specification, like letters on the drawing representing like parts.

The present invention relates to a device for automatically controlling the condition of another device. In the specific embodiment of the invention illustrated herein it appears as a temperature controlling thermostat, such as may be employed for example in maintaining an oven at a given desired temperature. It will be seen, however, that the principles involved in the invention are by no means limited to thacontrolling ot' a temperature condition, but may be plied equally to the controlling of pressure, volume, or other condition.

The condition controlling device of this in\'e ntion is essentially an electrical device and embodies among others the novel features of means for adjusting the state of condition to be maintained, means for pro- 'ducing accuracy by a device for multiplying the movement of the element controlled by the change of condition, and means whereby the electrical contact points of the device secure their eflective action without impeding in any way the movement of the element indicating the change of condition.

The exact nature of theinvention can best be seen from the accompanying specification and drawings describing and illustrating a temperature controlling thermostat embodying the invention in a preferred and specific 'form. and the extent of the invention will be defined by the accompanying claims.

The drawings represent a temperature controlling thermostat, together with :1 diagrammatic illustration of suitable electric circuits.

ln the drawings, Figure 1 is a vertical side elevation. partially in cross-section, of the entire thermostat: Fig. 2 is a vertical front elevation of the, device: Fig. 3 is a horizontal sectional view taken on the lines a*.r, Figs. 1 and 2: Fig. 4 is a diagrammatic view of the thermostat. and electrical means for operating the supply of heat, and suitable electric circuits for the same.

In the specific embodiment of the invention herein illustrated as a temperature controlling thermostat, A is a rigid framework offset at the lower end to present a lug a, and forked at the upper end to present two arms I), 12 forming a yoke.

The yoke b, 1) supports two rods b, If, both of which serve as guides and supports for the contact point frame 6 movable thereon. The rod 6 is provided with a thumb-nut l), stops I), I) abutting against the arms I), b and preventing longitudinal movement of the rod, and a lock nut l)", and has a screw-thread engagement with the contact point frame 1), whereby upon the rotation of the thumb-nut l) the contact point frame lfimay be. adjusted transversely of the frame and locked in position.

-,The contact point frame carries pivoted thereto as at 0, c, and insulated therefrom and from each other, two electric contact points c, c, which are held in their lower- .most position by stops c and which when point frame 12 are in electrical connection one with each contact point 0', and serve for the attachment thereto of the wires of an electric circuit or circuits.

In the device illustrated it is designed that the movable element which is controlled by the condition of the device, such for example as the tempcrature of an oven, shall upon opposite changes of the said condition, such for example as the rise or fall of the term perature, come into contactwith the proper one of the electric contact points c, and thereupon complete an electric circuit which, through intervening devices, shall act to restore the normal or desired condition.

In the device illustrated the movable element is an ordinary laminated long, thin fiat bar D, fastened at its lower end to the lug (t and bending at its upper end in 'opposite directions, accordingly as the temperature to be controlled rises or falls.

If the laminated arm D be placed in direct tact points o c, it would be ditlicult, if not impractical,.to obtain any very close adjust- October switches.

ment of the condition or temperature, becauseif the laminated arm be made of suflicie'nt length to have an appreciable movement at its upper end for a slight change in temperature, it would be found so delicate as to be easily affected by any local vibration to which it might be subjected, and unless it should be kept in a perfectly still position it would not capable of close adjustment. For this reason an auxiliary element, herein termed a multiplier, has been introduced between the free end of the laminated arm or operating element and the contact points. This permits the use of a short and stocky laminated arm, which is not easily affected by any jarring or vibration, and yet secures a close adjustment.

The multiplier is shown as a lever pivoted at f on thecontact point frame F, and made up of two pieces e, c, insulated from each other, the former of which carries a pin 0 cooperating with a longitudinal slot 1) in the cross-head d of the laminated arm D, and the latter of which is flattened at its upper end to vibrate between the contact points 0,

i c and come into engagement therewith.

An electrical connection with one branch of the electric circuit is made with the upper art c of the lever or multiplier in any suitable manner. tends from the part c to a pin F, in connection with a binding post f attached to but insulated from the contact point frame If.

The cross-head cl carries a flat spring d adjacent its upper surface, so that when the pin 6 rides out of the slot in the cross-head thesaid spring will hold the pin and pre vent the lever e, e from turning up side down, and also serves to guide the pin 6'' back into the slot (Z upon the return of the parts toward alined position.

The delicacy of the adjustment will depend, of course, upon the relative proportion of the parts, and especially upon the position of the pivot of the lever c, c With the arrangement shown the movement of the laminated-arm is multiplied about four times.

The general operation of the device illustrated may be best understood by reference I 4 to the diagrammatic illustration of Fig. 4,

where H represents the device, the condition of which is to be controlled. The condition herein illustrated is one of temperature, and the temperature is herein shown as dependent upon a resistance, part of which is shown at h, in an electric circuit, the main wires 1, 2 of which extend to a suitable source of electric energy, not shown.

The supply of current to'the resistance 71 is shown as directly controlled by a s'witcharm it operated by two magnets M, M, the construction and operation of which need not herein be described, but is fully set forth comparatively Herein the wire coil f ex- .action of the laminated arm,

in Patent No. 773,182, granted to me on 1904, for 'automatic electric The contact points (1, (1, through the binding posts I, 1; are connected by the circuit wires 3 and 4, one with each magnet M, M', while the contact arm 0' of the multiplier lever is connected by the circuit wire 5 with the main line wire 1. It will thus be seen that when it is desired to maintain the device H at a given temperature the thumb screw 7; is turned to adjust the contact point frame 7) and the parts carried thereby to such position that the contact arm c of the multiplier lever shall be centrally between the contacts (1', 0 when the laminated'arm D is in the position resulting from the desired temperature of the device H. In this position current. is supplied to the resistance It, and the switch-arm h is in engagement with the lower contact completing the circuit through the resistance.

If the temperature rises above the desired point the laminated arm H will move in. one or the other direction, according to its construction, as for example to the left, throwing the multiplier into engagement with the contact point 0, connected to the wire 3. thereupon energizing the magnet M and cutting out the resistance It, whereupon th. temperature will begin to fall, and then the laminated arm IT will swing in the opposite direction toward the right, bringing the multiplier into engagement with the contact point in connection with the wire r. thus energizing the magnet M-and throwing in the resistance h. In this manner the temperature of the device II will be kept substantially constant at the desired degree.

It is important that the contact points with which the laminated arm or multiplier come into engagement shall be so arranged that they do not impede the movement or and yet that. they shall be effective in producing prompt action with a slight movement of the thermostat. It is necessary that the moving element engaging with the contact points shall pass freely from one extreme position to another as it may be moved by the changes in condition or temperature at whatever point of adjustment the apparatus may be set, without aifecting the sensitiveness of the de-" rice or the closeness of the adjustment or regulation to the desired temperature. In the device illustrated herein, for example, when the device H heats up the laminated arm will come over and cause the multiplier to press against the contact points, and to continue its movement after making contact, notwithstanding the heat supplied is innuediately cut off or reduced at the moment of contact, because with almost any arrangement or source of heat the stored energy in the heater, when electric or other heater is used, will continue to give out heat and i takes at low temperature.

10 points limit the travel of the laminated'arm *ferTnnltiplier when the current is cut off, unless the contact points are removed the laminated arm will be prevented from returning to its normal position, which it By making the contact points movableto allow of the free passage of the laminated arm or multiplier after it comes into contact these difliculties are avoided. The contact points when pivoted as shown are always in proper position and are readily moved out of the way by the laminated arm itself when, as is usual, a movement greater than necessary to make contact takes place.-

A continued engagement between the-pin c of the multiplier and the slot I] of the cross-head on the laminated arm throughout extended ranges of movement of the laminate dvarm would produce binding of the 0 parts and require a long slot. By the construction illustrated the pin 0 remains in the slot for a limited range of movement, but when the movement increases the pin leaves the slot and rides along on the top of '5 the cross-head and beneath the spring (Z preventing the multiplier arm from assuming a horizontal position or turning completely over. -When the parts return to position where a contact is to be made the pin 40 will return into the slot under the guiding influence of the spring.

While in the specific embodiment of the invention illustrated an electric heater has been shown, it is obvious that the thermo- -5 stat may be applied to any other heater, and

.While :in the said devlce electro-magnets are shown for controlling the heat, yet it is obvious also that any other motor or actuating device for performing the functions neco essary may be employed. The invention in fact is applicable to various devices wherein a change of various conditions, such as heat, pressure or volume, is to be controlled. It is only. necessary that there should be mov- 5 ablearm or member operating upon a change in condition, the movement of which may be utilized in connection with. the electric contacts of the device] The invention presents a device of such a nature as to be made (30 very accurate and sensitive, and which has a performance at any given point fer which it may be set, and which in the event of the ca operation being discontinued, such for ex ample as cutting off the heat supply entirely when applied to the control of heat or temperature does not in any \'a v need attenti )n to insure its working as before when ever the source of energy is again supplied.

Having described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. A condition controlling device comprising a support, a pair of contacts pivotally mounted therein, a circuit closing element movable to engage either contact according to variations in the conditions to be controlled, said contacts being arranged to yield to a continued movement of said circuitclosing member, and means for limiting the pivotal movement of said contacts in the opposite direction.

2. A condition controlling device comprising a support, a pair of contacts mounted in said support, provided with overlapping ends, said ends being separated from cach other, and a circuit closing element movable to engage either of said overlapping ends according to variations in the conditions to be controlled, said contacts being arranged to yield to a continued movement of said circuit closing member.

3 A condition controlling device comprising a support, a pair of contacts pivotally mounted therein and beveled at their ettcctivo ends, a circuit closing element movable to engage either contact according to variations in the conditions to be controlled, said contacts being arranged to yield to a continued movement of said circuit closing member, and stops for limiting the movement of each member in the opposite direction.

4. A condition controlling device comprising a support, a pair of contacts pivotally mounted thcren1,said support being provided with stops to limit the pivotal movcmcnt of said contacts, and a circuit closing clement movable to engage either contact according to the variations in the conditions to bo-controlled, said contacts being arranged to yield to a continued movement of said circuit closing element.

A condition controlling device comprising a support, a pair of contacts mounted in said support, provided with overlapping ends, said cnds'being separated from each other, and a circuit closing clement movable to engage either of said overlapping ends according to variations in the conditions to be controlled, said contacts being arranged to yield to a continued movement of said circuit closing member, and means for limiting the movement of each contact in the opposite dependentcircuit tions in the conditions to be controlled, a cirl cuit closing element, "means for connecting 1 said elements, and means for maintaining the i operative relation of said elements under exl cessive movement of the operating element. l

7. A conditioncontrolling device coinprising a support, a pair of contacts pivotally mounted therein, and each ar 'anged to cont trol an independent circuit, an element mov l able in directions corresponding to variations l in the conditions to be controlled, and a cir- 1 cuitclosing clement operated by the first mentioned element and arranged to move in 1 reverse directions thereto to engage eithert contact, said contacts being so mounted as to yield to a continued movement of the circuit 1 closing member, means for returning each contact to its normal position thereafter. means for limiting the pivotal movement of said contacts in the opposite direction.

8. A condition controlling device comprising a support, a pair of contacts pivotally mounted therein. and each arranged to control an independent circuit. a thermostat member movable in directions coi'reiponding to the conditions to be controlled. :1 multiplying lever having its longer arm arranged to engage either contact, said contacts being so mounted as to yield to a continued movement of said multiplying lever and in the direction of movement thereof, means foitreturning each contact to normal positionthereafter. and means for connecting the short arm of said multiplying lever to the free end of said thermostat. member, the point. of 'connection between said lever and said member being automatically sliiftable during the operation of the parts.

t). A condition controlling device comprising a support, a pair of contacts supported thereby, and each arranged to control an iul dependent circuit, a thermostat member mo vi able in directions corresponding to the coin l ditions to be controlled, a multiplying lever I having a pin and slot connection between its t shorter arm and the free end of said thermo- I stat member, and the longer arm arranged to engage either contact, said contacts being t so-arrange(.l as to yield to a continued inovet merit of said multiplying lever and in the dil l t l rection of movement thereof. and means on either side of said slot for guiding said pin. 10. A condition cont-rolling device comprising a support. a pair of contacts supported thereby, and each arranged to control an iiia thermostat member movable iii directions corresponding to the condi tions to be controlled. a cross head on the free end of said thermostat member and pro vided with a centrally disposed open longitrul'inal slot.a confining spring mounted upon i and extending across the top of the crow l head, a multiplying lever having its shorter i arm provided with a pin cooperating with i said slot. and contro ing said spring when i prising a support,

ing a support.

thereby and each out of engagement with said slot, the longer arm of said lever being arranged to engage either contact, said contacts being arranged to yield to a continued movement of said multiplying lever.

11. A temperature controlling device coma thermostat member mounted therein, a carrier also mounted therein, means for adjusting said carrier in a direction pa 'allel with the line of movement of said thermostat, a pair of contacts mounted on said carrier, :1 multiplying lever mounted on said carrieand having one arm in engagement with said thermostat member, the other arm being normally between said contacts and arranged to engage either of them, said contacts being constructed to yield to a continued movement of said lever.

12. A. temperature controlling device coinprising -a support, a thermostat member mounted therein, a carrier also mounted therein, means for adjusting said. carrier in a direction parallel with the line of movement of said thermostat, a pair of contacts mounted on said support, mounted on said carrier and having one arm in engagement with said thermostat member, the othe' arm being normally between said contacts, and arranged to engage either of them, said contacts being each supported by a pivot, whereby it will yield to a continued movement of said lever, and means for returning each contact to its normal position after the passage of said arm.

l3. An adjustable ten'iperature controlling device comprising a frame, a thermostatic arm mounted at the lower end of said frame, a support movable on and transversely adjustable of said frame at its upper end, a pair of contacts pivotally mounted upon said support, a multiplying lever pivoted upon said support and having its shorter arm in a multiplying lever,

loose engagement'witli. the free end of the I means for returning eacli pivoted contact to normal position after the passage of said arm,

14. A condition controlling device comprising a support. a pair of contacts pivotally mounted therein, a circuit closing element movable toengage either contact according to variations in the conditions to be coiitrolled. said contacts being arranged to yield to a continued movement of said circuit closing member. means for limiting the pivotal inowniciit pt said contacts in the opposite direction. circuits controlled by saidcontacts, and means controlled by said circuits for varying the conditions to be controlled.

15. A condition controlling device comprisa pair of contacts carried dependent circuit. an operating elementmow able in directions corresponding to variations arranged to control an niin Eh-'2 conditions to be controlled, a circuit 1 closing element, means for Connecting said elen'xents means for maintaining the operative relation said elements under excessive movement of the operating element, circuits controlled by said contacts, and means controlled by saxd circuits for varying file conditions to be-contmiied.

- in testimonywhereof, 3 have sigma my name to thls speclficatmn; in the presence of 1 1 two subscnbmg wltncsses.

JAI'flES I. AYE'E.

Witnesses CLAREN CE D. WALKER, CHARLES W. ir-zcrmzzns. 

